While it’s free to set up a basic account on LinkedIn, the site is in business to make money.One way LinkedIn earns money is by charging people to use its internal email system called Inmail to contact almost anyone who has a profile on LinkedIn. (People with profiles on LinkedIn can opt out of receiving Inmail, but virtually no one does.)

To use LinkedIn’s Inmail feature, you do not need to be connected to a person on LinkedIn, and you do not need to have the person’s contact information. Simply click on the prominent blue Inmail button in a person’s profile, type your message, pay the fee, and LinkedIn will deliver your email to that person. (While LinkedIn will deliver your message, it will not reveal that person’s contact information to you.)

If you have a Premium (i.e., paid) account on LinkedIn, you can send a small number of Inmails each month at no charge.If you have a Basic (i.e., free) account, LinkedIn charges you about $12 for each person you contact using Inmail.

While LinkedIn’s email system is expensive, LinkedIn guarantees a response from the person within 7 days, or the company will refund your payment.